A historical example would be transmitting written text via Morse code- instead of having someone carry the text on paper, it is converted to (or encapsulated as) Morse codeat one end and converted back to written text at the other.

A more recent example would be tunnelling IPv6 over anIPv4network that does not support IPv6 natively. Tunnelling techniques such as 6to4 or 6rd are used to encapsulate IPv6 in the absence of native dual-stack support.